High Transferrin Receptor Research Articles

Transferrin Receptor Promotes Endometrial Cancer Proliferation by Activating the Iron-Dependent PI3K/AKT/mTOR Signaling Pathway.

Aberrant iron metabolism is frequently observed in cancers, including endometrial cancer (EC). However, the role of transferrin receptor (TFRC), a key regulator of iron metabolism, remains unclear in endometrial cancer. We found transferrin receptor expression was significantly upregulated in endometrial cancer tissues compared to adjacent nontumor tissues, and high transferrin receptor levels were associated with poor prognosis. Functional studies revealed that transferrin receptor knockdown impaired endometrial cancer cell proliferation invitro and invivo, while transferrin receptor overexpression enhanced endometrial cancer cell proliferation. Mechanistically, transferrin receptor activated the PI3K/AKT/mTOR signaling pathway, as its knockdown suppressed the pathway, and rapamycin, an mTOR inhibitor, reversed transferrin receptor-induced pathway activation and proliferation. Modulation of the labile iron pool by ferric ammonium citrate (FAC) or deferoxamine (DFO) rescued transferrin receptor-induced biological effects. Additionally, AURKA was identified as a regulator of transferrin receptor expression. These findings demonstrate the oncogenic role of transferrin receptor in endometrial cancer and suggest that targeting iron homeostasis and the PI3K/AKT/mTOR pathway may represent potential therapeutic strategies for endometrial cancer.

Iron metabolism in a mouse model of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains the most prevalent type of primary liver cancer worldwide. p53 is one of the most frequently mutated tumor-suppressor genes in HCC and its deficiency in hepatocytes triggers tumor formation in mice. To investigate iron metabolism during liver carcinogenesis, we employed a model of chronic carbon tetrachloride injections in liver-specific p53-deficient mice to induce liver fibrosis, cirrhosis and subsequent carcinogenesis. A transcriptome analysis of liver carcinoma was employed to identify p53-dependent gene expression signatures with subsequent in-depth analysis of iron metabolic parameters being conducted locally within liver cancers and at systemic levels. We show that all mutant mice developed liver cancer by 36-weeks of age in contrast to 3.4% tumors identified in control mice. All liver cancers with a p53-deficient background exhibited a local iron-poor phenotype with a “high transferrin receptor 1 (Tfr1) and low hepcidin (Hamp)” signature. At systemic levels, iron deficiency was restricted to female mice. Additionally, liver tumorigenesis correlated with selective deficits of selenium, zinc and manganese. Our data show that iron deficiency is a prevalent phenomenon in p53-deficient liver cancers, which is associated with alterations in Hamp and Tfr1 and a poor prognosis in mice and patients.

Iron promotes isocitrate dehydrogenase mutant glioma cell motility

Iron promotes isocitrate dehydrogenase mutant glioma cell motility

Inhibiting ferroptosis mitigates sheep sperm freezing damage.

To evaluate the roles of apoptosis and ferroptosis in cryopreservation-induced damage to sheep sperm, with a focus on assessing the effectiveness of inhibitors targeting these pathways. Initial analysis compared the expression of apoptotic marker Cleaved-caspase3 (CL-caspase3) and ferroptotic marker Transferrin receptor (TFRC) between fresh and cryopreserved sheep sperm. Elevated CL-caspase3 expression and sustained high TFRC expression post-cryopreservation suggested concurrent occurrence of apoptosis and ferroptosis. Consequently, the study employed Deferoxamine Mesylate (DFO), ferrostatin-1 (Fer-1), liproxstatin-1 (Lip-1), and the apoptosis inhibitor Z-VAD-FMK (Z-VAD) at concentrations ranging from 0 to 10 μM. Post-thaw assessments encompassed plasma membrane integrity, acrosome integrity, and ferroptosis biomarkers. Additional experiments were conducted to measure the expression of GPX4, a key regulator of ferroptosis. Optimal concentrations (2 μM for DFO, Fer-1, and Lip-1; 5 μM for Z-VAD) significantly improved sperm motility and membrane integrity. Among these, Fer-1 demonstrated the greatest efficacy, reducing reactive oxygen species (ROS), lipid peroxidation, and Fe2+ levels. Z-VAD primarily decreased ROS but was less potent than ferroptosis inhibitors. Notably, Glutathione Peroxidase 4 (GPX4) expression was reduced post-cryopreservation, while Fer-1 supplementation restored its levels to those comparable with fresh sperm. Both apoptosis and ferroptosis play critical roles in sheep sperm cryopreservation. Fer-1 effectively enhanced cryopreservation outcomes by inhibiting ferroptosis, as evidenced by the restoration of GPX4 expression and improvement in sperm quality indicators. These findings highlight ferroptosis inhibition as a promising strategy for preserving genetic material, with implications for animal breeding and biodiversity conservation.

The TFRC as a prognostic biomarker and potential therapeutic target in cervical cancer: a preliminary study.

Early detection and treatment of CIN or early-stage cervical cancer lead to better clinical outcomes compared to treating advanced-stage patients. Thus, specific biomarkers for the diagnosis and prognosis of CIN and early-stage cervical cancer should be urgently explored. We analyzed tumor based on genes closely related to OS in the database with GSE63514, GSE7803, GSE9750 and TCGA data sets, the top 20 core genes were screened out. Notably, transferrin receptor (TFRC) emerged as a prioritized candidate due to its dual role in cellular iron homeostasis and oncogenic signaling. However, the exact role of TFRC in the development and progression of cervical cancer remains unclear. We then used various bioinformatics methods and mathematical models to analyze those data, aiming to investigate the clinical significance of TFRC in cervical cancer and illustrate its association with tumor immunity. In addition, the molecular function and mechanisms of TFRC were revealed by gene ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analysis. Immunohistochemistry was employed to assess TFRC protein expression in 19 cervical cancers, 16 HSILs and 15 normal cervical tissues. TFRC was highly expressed in CESC in the TCGA and GSE9750 datasets. Meanwhile, the expression of TFRC was correlated with pathological stage, lymph node metastasis, malignant degree of cervical lesions and HPV infection status. Our analysis confirmed that TFRC expression was higher in CESC tissues compared to normal cervical tissues, and it was also elevated in HSIL relative to normal tissues, as determined by IHC staining. Increased TFRC expression was linked to decreased overall survival (OS) (p = 0.024), disease-specific survival (DSS) (p = 0.009), and progression-free interval (PFI) (p = 0.007) in CESC patients. In different clinical stages, pathological T stages, and pathological N stages, higher TFRC expression was significantly associated with worse survival for OS and DSS. We constructed a nomogram model, TFRC contributed significantly to the prognosis and exhibited good predictive power for the OS and the DSS. Finally, we confirmed that immunosuppression in cervical cancer is closely related to high TFRC expression. TFRC exhibits significant diagnostic and prognostic value in cervical cancer.

Selenium deficiency is associated with anemia in heart failure patients - The HARVEST Study

Abstract Background Heart failure (HF) patients with anemia have worse clinical outcomes with increased hospitalization rates, decreased exercise tolerance, and higher mortality compared to those without anemia. Previous studies have indicated a correlation between selenium deficiency and anemia in healthy elderly individuals and in pregnant women. The BIOSTAT-CHF study reported that HF patients with higher selenium levels were less likely to have anemia or iron deficiency. These studies suggest that selenium deficiency can lead to the development of anemia. However, studies regarding this association in HF patients are limited. Purpose The purpose of this study was to examine the relationship between selenium deficiency, measured by selenoprotein P (SELENOP) levels, and anemia, hemoglobin levels, and iron state in subjects with acute HF. Methods SELENOP, a well-validated plasma marker of selenium status, was measured in 320 subjects hospitalized for HF in the Swedish HeArt and bRain failure inVESTigation trial (the HARVEST study). Of these subjects, 310 had complete data on all covariates. Prior to analyses, skewed variables were ln-transformed. The relationships between continuous SELENOP levels and 1) Hb levels, 2) anemia (Hb < 115 g/L (women), < 130 g/L (men)), and 3) iron status (as measured by transferrin receptor 1 (TfR1) which increase in iron deficiency) were evaluated using multivariable logistic and linear regression models adjusting for age, sex and renal function (cystatin C). Additionally, selenium deficiency was defined as SELENOP levels in the lowest quartile and its association with anemia, hemoglobin, and iron state was explored in multivariable logistic and linear models. Results Anemia was present in 133 subjects (42.9%). SELENOP levels were positively correlated with hemoglobin levels (0.238; p = 2.3x10-5) and negatively associated with TfR1 levels (-0.238, p = 2.0x10-6). In multivariable linear regression models, each 1 standard deviation increase in SELENOP was linked to higher Hb levels and lower TfR1 levels (Table 1). Furthermore, selenium deficiency was associated with lower Hb levels, higher TfR1 levels, and higher odds of anemia in HF patients (Table 1). Conclusions In acute heart failure patients, lower levels of selenoprotein P were associated with lower hemoglobin levels, higher transferrin receptor 1 levels, and a higher prevalence of anemia.

Iron Deficiency is Related to Depressive Symptoms in United States Nonpregnant Women of Reproductive Age: A Cross-Sectional Analysis of NHANES 2005-2010

BackgroundFindings of the association between iron status and depressive symptoms in nonpregnant women of reproductive age (WRA) are equivocal, limited by a small sample size, or did not consistently control for confounders. ObjectiveWe tested the association between iron status and depressive symptoms in WRA with the NHANES data (2005-2010). MethodsNonpregnant WRA (20-44 y) with complete data on iron (ferritin and transferrin receptor (TfR)) and anemia (hemoglobin) biomarkers, depressive symptoms (Patient Health Questionnaire-9), and sociodemographic variables were included. Logistic and negative binomial regressions were used to estimate presence (odds ratios) and magnitude (prevalence ratios), respectively, for depressive symptoms by iron deficiency (ID)/anemia/ID anemia in the total sample and stratified by poverty:income ratio (≤ 1.85 or >1.85). ResultsAmong 2516 females, the prevalence of ID was 8 to 16% (depending on the iron biomarker used), of anemia 8%, of which 52 to 65% were also ID. The prevalence of depressive symptoms was 10%. Crude logistic models showed that females with ID (TfR ≥ 8.3 mg/L or body iron <0 mg/kg) from the total sample had 1.82 (95% confidence interval [CI]: 1.24, 2.68) and 1.62 (95% CI: 1.05, 2.48), respectively, higher odds of depressive symptoms than females with iron sufficiency; these associations were attenuated after adjustments for confounders. Adjusted negative binomial models showed that females with ID (TfR ≥ 8.3 mg/L) from the total and low-income samples showed 1.19 (95% CI: 1:00, 1.40) and 1.27 (95% CI: 1.03, 1.58), respectively, higher prevalence ratios of depressive symptoms scores than females with iron sufficiency. ConclusionsThese nationally representative data indicate that nonpregnant WRA with ID (based on high TfR) in the United States have higher prevalence of somatic depressive symptoms scores than those with iron sufficiency, especially if they are of low income.

Overexpressed transferrin receptor implied poor prognosis and relapse in gastrointestinal stromal tumors.

Ferroptosis, as a novel-induced programmed cell death, plays critical roles in the pathogenesis of cancers. However, the promising biomarkers of ferroptosis in gastrointestinal stromal tumor (GIST) remain to be elucidated. Herein, the expression of ferroptosis-related genes was analyzed in GIST. Among the 64 ferroptosis-related genes, transferrin receptor (TFRC) expression presented a remarkable upregulation in high-risk patients through Gene Expression Omnibus (GEO) dataset analysis, as well as its significant change after imatinib was treated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of TFRC-relevant genes revealed that TFRC expression was closely associated with cell growth pathways and metabolism-related pathways. Furthermore, patients at high risk of recurrence were more likely to exhibit high TFRC expression by immunohistochemistry. Additionally, high TFRC expression indicated an undesirable state of patient relapse, which could serve as a powerful significant independent predictor of recurrence-free survival (RFS). In summary, we systematically summarize the expression characteristics and clinical relevance of TFRC and show that TFRC can be used as a prognostic factor, which can be considered a potential therapeutic target in GIST.

High transferrin receptor expression marks tumors with increased immune-effector infiltration and expression of targetable checkpoint molecules: Results of a multi-cancer analysis in solid tumors.

2613 Background: The cell-surface transferrin receptor, TFR1, encoded by TFRC, imports iron-bound transferrin into cells to drive tumor proliferation. We have found worse prognosis with high TFRC expression across multiple tumor types. The mechanism by which TFRC drives tumor cell- intrinsic oncogenesis is multifactorial, but its interaction with the tumor microenvironment (TME) has not been studied. Here, we assessed TME infiltration by immune effector populations and immune checkpoint expression. Methods: Tissue samples underwent comprehensive molecular profiling at Caris Life Sciences: Next-gen sequencing of DNA (592 Gene Panel, NextSeq, or whole exome sequencing, NovaSeq), RNA- seq (NovaSeq, whole transcriptome sequencing, WTS) and immunohistochemistry. RNA deconvolution analysis by the Microenvironment Cell Populations (MCP)-counter method quantified immune populations to assess T cells, B cells, natural killer cells (NK) and myeloid dendritic cells (MDC). Analyses compared quartiles of TFRC mRNA expression between Q4 ( TFRC-H) high and Q1 ( TFRC-L) low expressors. Results: Among 27,607 patients with non-small cell lung cancer (NSCLC), 5,332 with prostate cancer (PC), and 14,287 with colorectal cancer (CRC), TFRC-H tumors were associated with high tumor mutational burden (TMB-high, ≥10 mutations/MB), and TP53 mutation (q&lt;0.05). Multiple immune checkpoint genes showed significantly higher expression in TFRC-H relative to TFRC-L in all tumor types, including CD274 (PDL1), LAG3, PDCD1LG2 (PDL2), and CTLA4 (Table; All values are statistically significant: q&lt;0.05). Moreover, TME assessment by MCP-counter showed significantly increased infiltration by total T cells, CD8+ cells, B cells, NK cells, and MDCs in TFRC-H (Table). Finally, among patients who received Check-point inhibitors (CPI), TFRC-L had improved survival (HR=0.807 (95% CI 0.76 – 0.85) p&lt;0.00001) in NSCLC but no difference was found in CRC or PC. Conclusions: Our study is the first to reveal the TME characteristics associated with TFRC expression in a variety of solid tumor types. We found TFRC-H tumors have increased infiltration by immune effector populations but also express significantly higher levels of immune checkpoint molecules, highlighting immune exhaustion. Altered iron metabolism has been shown to promote tumorigenesis and here we identify a new role for TFRC in remodeling the TME. TFR1- targeting therapeutic agents are in clinical development and warrant further investigation in combination with CPIs. [Table: see text]

Serum Soluble Transferrin Receptor and Transferrin Levels among Regular Blood Donors

Background: The study evaluated the effects of regular blood donation on serum transferrin and soluble transferrin receptor levels at Wenchi Methodist Hospital. Methods: This was a hospital-based cross-sectional study conducted at the Medical Laboratory Department of the Wenchi Methodist Hospital in the Bono Region of Ghana. A total of eighty-nine (89) venous blood samples from apparently healthy blood donors were analyzed. Complete blood count parameters were analyzed using an automated haematology analyzer and serum transferrin and transferrin receptor using ELISA. The data were analyzed using SPSS version 22.0. Results: Haemoglobin (p&lt;0.001) and HCT (p=0.004) were significantly lower among the regular blood donors compared with the first-time donors. Regular blood donors had relatively higher serum transferrin (p&lt;0.001) and soluble transferrin receptor levels (p&lt;0.001). A negative correlation was observed between Hb and serum transferrin (r=-0.552, p&lt;0.001), as well as Hb and serum soluble transferrin receptor (r=-0.552, p&lt;0.001). Remunerated donors had lower Hb (p=0.001) and HCT% (p=0.001) but a higher transferrin receptor (p=0.041) than non-remunerated donors. Conclusion: Regular blood donors had relatively lower erythrocyte parameters but higher serum transferrin and soluble transferrin receptors, indicating a possible reduction in serum iron and iron stores. Moderate negative correlations exist between Hb and both transferrin and soluble transferrin receptors. Again, remunerated donors had lower erythrocyte parameters but higher transferrin and soluble transferrin receptors than non-remunerated donors. Periodic assessment of iron parameters among regular blood donors is recommended. A future longitudinal study to assess the entire iron profile of regular blood donors is recommended. Doi: 10.28991/SciMedJ-2022-04-03-01 Full Text: PDF

LncRNA RP1-86C11.7 exacerbates the glioma progression and oncogenicity by hsa-miR-144-3p/TFRC signaling.

LncRNA RP1-86C11.7 exacerbates the glioma progression and oncogenicity by hsa-miR-144-3p/TFRC signaling.

Tumor cell-imposed iron restriction drives immunosuppressive polarization of tumor-associated macrophages

BackgroundTumor-associated macrophages (TAM) are immunosuppressive cells that contribute to impaired anti-cancer immunity. Iron plays a critical role in regulating macrophage function. However, it is still elusive whether it can drive the functional polarization of macrophages in the context of cancer and how tumor cells affect the iron-handing properties of TAM. In this study, using hepatocellular carcinoma (HCC) as a study model, we aimed to explore the effect and mechanism of reduced ferrous iron in TAM.MethodsTAM from HCC patients and mouse HCC tissues were collected to analyze the level of ferrous iron. Quantitative real-time PCR was used to assess M1 or M2 signature genes of macrophages treated with iron chelators. A co-culture system was established to explore the iron competition between macrophages and HCC cells. Flow cytometry analysis was performed to determine the holo-transferrin uptake of macrophages. HCC samples from The Cancer Genome Atlas (TCGA) were enrolled to evaluate the prognostic value of transferrin receptor (TFRC) and its relevance to tumor-infiltrating M2 macrophages.ResultsWe revealed that ferrous iron in M2-like TAM is lower than that in M1-like TAM. In vitro analysis showed that loss of iron-induced immunosuppressive M2 polarization of mouse macrophages. Further experiments showed that TFRC, the primary receptor for transferrin-mediated iron uptake, was overexpressed on HCC cells but not TAM. Mechanistically, HCC cells competed with macrophages for iron to upregulate the expression of M2-related genes via induction of HIF-1α, thus contributing to M2-like TAM polarization. We further clarified the oncogenic role of TFRC in HCC patients by TCGA. TFRC is significantly increased in varieties of malignancies, including HCC, and HCC patients with high TFRC levels have considerably shortened overall survival. Also, TFRC is shown to be positively related to tumor-infiltrating M2 macrophages.ConclusionsCollectively, we identified iron starvation through TFRC-mediated iron competition drives functional immunosuppressive polarization of TAM, providing new insight into the interconnection between iron metabolism and tumor immunity.

Transferrin receptor (TFRC) is essential for meiotic progression during mouse spermatogenesis.

Meiosis is a highly conserved process, and is responsible for the production of haploid gametes and generation of genetic diversity. We previously identified the transferrin receptor (TFRC) in the proteome profile of mice neonatal testes, indicating the involvement of the TFRC in meiosis. However, the exact molecular role of the TFRC in meiosis remains unclear. In this study, we aimed to determine the function of the TFRC in neonatal testicular development by TFRC knockdown using the testis culture platform. Our results showed high TFRC expression in 2-week testes, corresponding to the first meiotic division. Targeting TFRC using morpholino oligonucleotides resulted in clear spermatocyte apoptosis. In addition, we used the chromosomal spread technique to show that a deficiency of TFRC caused the accumulation of leptotene and zygotene spermatocytes, and a decrease of pachytene spermatocytes, indicating early meiotic arrest. Moreover, the chromosomes of TFRC-deficient pachytene spermatocytes displayed sustained γH2AX association, as well as SYCP1/SYCP3 dissociation beyond the sex body. Therefore, our results demonstrated that the TFRC is essential for the progression of spermatocyte meiosis, particularly for DNA double-stranded break repair and chromosomal synapsis.

CSIG-16. SEXUAL DIMPORHISM IN IRON ACQUISITION IN GLIOBLASTOMA

Abstract Glioblastoma (GBM) is the most aggressive brain cancer. Sex differences in incidence and clinical outcomes have been reported, however, our knowledge of contributing mechanisms is limited. Iron acquisition is key to robust tumor growth. Upregulation of Transferrin (Tf, iron transport protein)/Transferrin receptor (TfR) is found in multiple different cancers. We have identified H-ferritin (FTH1) as involved in iron transport and explore its uptake in GBM in this study. We interrogated iron uptake in a syngeneic orthotopic mouse model (GL261 cells) using male and female mice. After the tumors were established, radioactive 125I labeled Tf and FTH1 proteins were injected retro-orbitally in the mice. After 24 hours, tumors were removed, homogenized and analyzed for Tf and FTH1 uptake. There was a significant difference in Tf uptake into the tumor versus matched non-tumor tissue in both males and females and the uptake in the tumors was 1.5-fold higher in males than females. There was no significant difference in FTH1 uptake between male and female tumors nor between tumor and matched non-tumor brain tissue. Binding analyses were performed on homogenized samples of human male and female GBM tissue samples using 125I labeled Tf and FTH1. Tumors from males had increased binding of both proteins compared to tumors from females. We next queried the TCGA database and found in females, high TfR expression was associated with poor survival but not in males. TCGA database revealed a robust expression of Tim1, a putative receptor for FTH1, but its expression did not relate to survival. In summary, this study demonstrates FTH1 binding to GBMs and sexual dimorphism in iron acquisition via Tf and survival.

NIR Photodynamic Destruction of PDAC and HNSCC Nodules Using Triple-Receptor-Targeted Photoimmuno-Nanoconjugates: Targeting Heterogeneity in Cancer.

Receptor heterogeneity in cancer is a major limitation of molecular targeting for cancer therapeutics. Single-receptor-targeted treatment exerts selection pressures that result in treatment escape for low-receptor-expressing tumor subpopulations. To overcome this potential for heterogeneity-driven resistance to molecular targeted photodynamic therapy (PDT), we present for the first time a triple-receptor-targeted photoimmuno-nanoconjugate (TR-PIN) platform. TR-PIN functionalization with cetuximab, holo-transferrin, and trastuzumab conferred specificity for epidermal growth factor receptor (EGFR), transferrin receptor (TfR), and human epidermal growth factor receptor 2 (HER-2), respectively. The TR-PINs exhibited up to a 24-fold improvement in cancer cell binding compared with EGFR-specific cetuximab-targeted PINs (Cet-PINs) in low-EGFR-expressing cell lines. Photodestruction using TR-PINs was significantly higher than the monotargeted Cet-PINs in heterocellular 3D in vitro models of heterogeneous pancreatic ductal adenocarcinoma (PDAC; MIA PaCa-2 cells) and heterogeneous head and neck squamous cell carcinoma (HNSCC, SCC9 cells) containing low-EGFR-expressing T47D (high TfR) or SKOV-3 (high HER-2) cells. Through their capacity for multiple tumor target recognition, TR-PINs can serve as a unique and amenable platform for the effective photodynamic eradication of diverse tumor subpopulations in heterogeneous cancers to mitigate escape for more complete and durable treatment responses.

Transferrin Receptor and Cellular Iron are Potential Molecular Targets for Diagnosis and Treatment of Lung Cancer

Lung cancer is one of the leading causes of cancer death. Most current treatments have debilitating side effects with poor selectivity and pharmacodynamic properties. To develop more effective and safer anticancer drugs, we synthesized trioxane (DMR) and dioxazinane (HSM), both novel Artemisinin (ART) analogs. These analogs induced apoptosis in cancer but not normal lung cells and was reactive oxygen species (ROS) dependent. We also showed that cancer cells have higher transferrin receptor (TfR) expression compared to normal cells. We hypothesize high levels of TfR expression and [iron]i are responsible for the cancer specific effects of analogs. To study this, we confirmed iron’s role in ART analog‐induced apoptosis. We also knocked out TfR in cancer cells and overexpressed TfR in normal cells.Confluent normal (BEAS2B) and cancer (A549) human lung cells were treated (18 H) with 10μM of DMR, HSM ±Deferoxamine (DFO, iron chelator; 10 μM). [Iron]i was assessed in cell lysates using a colorimetric assay (Biovision, CA). Cell death was assessed by i) staining with FITC‐Annexin V (AV, apoptosis), propidium iodide (PI, cell death), followed by imaging, and quantification using flow cytometry and/or microscopy (Image J) and ii) measuring Lactate dehydrogenase (LDH) release. Cells were transfected with CRISPR/Cas9 overexpression (OE) or knockout (KO) plasmid (Santa Cruz, TX) containing Green Fluorescent Protein (GFP). Co‐transfection with HDR plasmid allowed for puromycin selection. Transfection efficiency was assessed using RT‐PCR, Western blot and GFP expression.A549 cells had 7‐fold more [iron]i than BEAS2B cells. This was essential for the apoptotic effects, as chelating iron with DFO prevented ART analog‐induced cell death (% AV+ A549 cells, 18 H: HSM: 54±4; HSM+DFO: 1±0.5; DMR: 32±3; DMR+DFO: 0.3±0.1, n≥3). KO of TfR in A549 cells yielded a low transfection efficiency (10%, Image J). Western blot of cell lysates did not show a significant reduction in TfR protein expression. Co‐transfection with HDR plasmid followed by puromycin selection increased transfection efficiency. However, there was increased cell death in TfR KO cells in culture (72 H, PI+ cells; mean pixel intensity (mpi), control: 15±0.2; GFP: 19±2, TfR KO: 49±42; n=3). Overexpression of TfR in BEAS2B cells yielded a higher transfection efficiency (~25%; Image J and RT‐PCR). Similar to TfR KO in A549 cells, after 72 H, there was a marked increase in cell death in TfR OE BEAS2B (PI+ cells (mpi), control: 18±2; GFP: 13±4, TfR OE: 83±20; n=3). TfR overexpression in normal lung cells possibly resulted in iron overload and ferroptosis.Our findings demonstrate that abnormal TfR expression and the associated changes in iron uptake induces death in normal and cancer cells, highlighting its importance in cell survival and proliferation. Understanding the role of TfR and iron in carcinogenesis will help develop potent therapeutic drugs to treat cancer, a disease that accounts for ~ 9 million deaths annually. Further, synthesizing novel analogs such as DMR‐tagged transferrin will provide specific and efficient drug delivery to cancer cells.Support or Funding InformationAPS‐STRIDE (Grant #1 R25 HL 115473‐01); NSSRP BenU Funds

Intestinal permeability and inflammation mediate the association between nutrient density of complementary foods and biochemical measures of micronutrient status in young children: results from the MAL-ED study

ABSTRACTBackgroundEnvironmental enteric dysfunction (EED) is thought to increase the risk of micronutrient deficiencies, but few studies adjust for dietary intakes and systemic inflammation.ObjectiveWe tested whether EED is associated with micronutrient deficiency risk independent of diet and systemic inflammation, and whether it mediates the relation between intake and micronutrient status.MethodsUsing data from 1283 children in the MAL-ED (Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health) birth cohort we evaluated the risk of anemia, low retinol, zinc, and ferritin, and high transferrin receptor (TfR) at 15 mo. We characterized gut inflammation and permeability by myeloperoxidase (MPO), neopterin (NEO), and α-1-antitrypsin (AAT) concentrations from asymptomatic fecal samples averaged from 9 to 15 mo, and averaged the lactulose:mannitol ratio z-score (LMZ) at 9 and 15 mo. Nutrient intakes from complementary foods were quantified monthly from 9 to 15 mo and densities were averaged for analyses. α-1-Acid glycoprotein at 15 mo characterized systemic inflammation. Relations between variables were modeled using a Bayesian network.ResultsA greater risk of anemia was associated with LMZ [1.15 (95% CI: 1.01, 1.31)] and MPO [1.16 (1.01, 1.34)]. A greater risk of low ferritin was associated with AAT [1.19 (1.03, 1.37)] and NEO [1.22 (1.04, 1.44)]. A greater risk of low retinol was associated with LMZ [1.24 (1.08, 1.45)]. However, MPO was associated with a lower risk of high transferrin receptor [0.86 (0.74, 0.98)], NEO with a lower risk of low retinol [0.75 (0.62, 0.89)], and AAT with a lower risk of low plasma zinc [0.83 (0.70, 0.99)]. Greater nutrient intake densities (vitamins A and B6, calcium, protein, and zinc) were negatively associated with EED. Inverse associations between nutrient densities and micronutrient deficiency largely disappeared after adjustment for EED, suggesting that EED mediates these associations.ConclusionsEED is independently associated with an increased risk of low ferritin, low retinol, and anemia. Greater nutrient density from complementary foods may reduce EED, and the control of micronutrient deficiencies may require control of EED.

Intestinal Permeability and Inflammation Mediate Dietary Intake Associated Risks of Micronutrient Deficiencies at 15 Months: Results from the MAL-ED Study (OR07-04-19)

Intestinal Permeability and Inflammation Mediate Dietary Intake Associated Risks of Micronutrient Deficiencies at 15 Months: Results from the MAL-ED Study (OR07-04-19)

Transferrin receptor-involved HIF-1 signaling pathway in cervical cancer.

Cervical cancer is one of the most prevalent gynecologic malignancies and has remained an intractable cancer over the past decades. We analyzed the aberrant expression patterns of cervical cancer using RNA-Seq data from The Cancer Genome Atlas (TCGA). A total of 3352 differently expressed genes (DEGs) were identified in 306 cervical cancer samples compared with 3 control samples, with 1401 genes upregulated and 1951 downregulated. Under Kaplan-Meier analysis, 76 out of these DEGs with a significantly different survival rate between patients with high and low expression groups were picked out and uploaded to perform Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, which identified a transferrin receptor (TFRC)-involved HIF-1 signaling pathway (p < 0.05). Clinical data analysis showed that high TFRC expression in cervical cancers was associated with incrementally advanced stage, tumor status, and lymph nodes (all p-values <0.05), while multivariate analysis revealed that TFRC remained an independent prognostic variable for poor overall survival. In conclusion, our data indicated that the TFRC-involved HIF-1 signaling pathway may play a crucial role in cervical cancer.

Issue Cover (September 2018)

Journal of NeurochemistryVolume 146, Issue 6 Issue CoverFree Access Issue Cover (September 2018) First published: 25 September 2018 https://doi.org/10.1111/jnc.14193 Read the full article: ‘Intracellular sorting and transcytosis of the rat transferrin receptor antibody OX26 across the blood–brain barrier in vitro is dependent on its binding affinity’ by A. S. Haqqani, G. Thom, M. Burrell, C. E. Delaney, E. Brunette, E. Baumann, C. Sodja, A. Jezierski, C. Webster, D. B. Stanimirovic (J. Neurochem. 2018, vol. 146(6), pp. 735–752) on doi: 10.1111/jnc.14482 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract Front cover: Background: Transferrin receptor (TfR) is enriched in brain endothelial cells and delivers transferrin across the blood-brain barrier (BBB). Antibodies against TfR can be used as molecular Trojan horses to deliver chemically or genetically attached therapeutic molecules across the BBB. However, high affinity TfR antibodies are primarily retained within brain endothelial cells, and are targeted for degradation in lysosomes, as shown in the cover image. Main findings: This study shows that lowering the affinity of the TfR antibody OX26 re-directs its intracellular traffic in brain endothelial cells (BEC) from degradative lysosomal pathway towards early and recycling endosomes. Implication: The finding suggests that anti-transferrin receptor antibodies should have medium to low affinity for the receptor when used for brain delivery of therapeutics. The lower affinity facilitates their escape from the lysosomal pathway in brain endothelial cells allowing transcytosis and release into the brain parenchyma. Image content: The image shows uptake of the rat anti-TfR antibody OX26 into the rat brain endothelial cell line (SV-ARBEC) and its co-localization with the molecular marker of lysosomes, lysosomal-associated membrane protein 1 (Lamp-1). Its affinity of 5 nM causes it to remain bound to TfR during its passage through the cell and results in trafficking to the lysosomal compartment. The antibody is labeled with the fluorescent dye AF680, shown in red. Lysosomal vesicles were identified by transducing SV-ARBEC with the Red Fluorescent Protein-labeled Lamp1, shown in green. Actin filaments were visualised using Alexa Fluor 488 Phalloidin, shown in blue. Cell nuclei are labeled with Hoechst, shown in turquoise. The image shows strong co-localization (yellow) of OX26 (5 nM) antibody with degradative lysosomes in successfully transduced cells. Image generated by Ewa Bauman, National Research Council of Canada. Read the full article ‘Intracellular sorting and transcytosis of the rat transferrin receptor antibody OX26 across the blood–brain barrier in vitro is dependent on its binding affinity’ by A. S. Haqqani, G. Thom, M. Burrell, C. E. Delaney, E. Brunette, E. Baumann, C. Sodja, A. Jezierski, C. Webster, D. B. Stanimirovic (J. Neurochem. 2018, vol. 146(6), pp. 735–752) on doi: 10.1111/jnc.14482 Volume146, Issue6September 2018 RelatedInformation